Floor structures for passenger aircraft usually consist of a multiplicity of transverse beams and seating rails. The seating rails serve to accommodate passenger seats, and run in the longitudinal direction of the aircraft over the transverse beams. The transverse beams are connected at their ends to lateral frame sections of the aircraft fuselage. Floor plates are positioned between the seating rails on the transverse beams. As shown in FIG. 1 support struts 2 can be provided for the vertical support of the floor structure 4. In the majority of cases the support struts 2 are supported via a foot section 6 on an underfloor frame section, not shown, and are connected via a head section 8 with the transverse beams of the floor structure 4. Normally they serve to accommodate axial compressive forces Fa introduced in the head section 8 along the vertical axis z of the aircraft. In the event of a crash, or an emergency landing with the undercarriage retracted, i.e. with direct contact of the underfloor region with the ground, as a result of a deformation of the frame sections in the underfloor region large compressive loads Fn can be introduced axially in the region of the foot section 6 into the support struts 2 such that these, as shown in FIG. 1b, are torn out of their head anchorages and penetrate the cabin floor laid down on the floor structure 4, signifying a hazard to the crew members and passengers in this region.
In the applicant's German patent application DE 10 2006 058 377 A1 is shown a support strut designed as a cylindrical Samer rod, which is covered with a fabric net. In the event of an unusual axial tensile loading as a consequence of a an emergency landing the fabric net serves as a quasi capture net, and in the event of damage to the Samer rod prevents the structural elements connected with one another via the Samer rod from being separated from one another. The Samer rod and in particular the fabric net are extremely well suited for purposes of stabilising the aircraft structure in the event of unusual tensile loads, but only to a limited extent for purposes of avoiding a hazard for the cabin personnel or passengers if extraordinary compressive loads occur.
From the German patent application DE 10 2007 028 098 A1 it is of known art to support a floor structure in the aircraft fuselage only by means of horizontal struts or bars, which extend from their ends on the transverse beams. The transverse beams are indirectly connected via the bars to lateral frame sections. There is no direct attachment of the transverse beams to the frame sections or the vertical support struts. However, this design is critical in the event of a crash in that no vertical support of the floor structure is provided.
The object of the present invention is to create a support strut for the support of a floor structure of an aircraft, which removes the above-cited disadvantages and in the event of unusual compressive loading, occurring, for example in the event of a crash, does not penetrate the floor.